My house voltage jumps up and down from 210volts to 243 volts is this OK

Why are you asking this question?

Are you experiencing some type of trouble?

Are you here in the U.S.A?

Usually voltage and amperage is delivered within a tolerance of +/- 10% so on the low end it would be 216 volts and on the high end it would be 264 volts.

Is it a spike drop and then recovery or a slow fluctuation? Is there a large plant next door? If you have a large pump, compressor or other large power using device, it could drop to 210 but that would be at the very low end and could cause damage to motors.

Dear donf thank your for your answer I am in Australia and I am setting up solar so I purchased a ms-6115 multifunction power meter to check the watts on all the items I have running and found this voltage problem and not being a sparky I thought I may be getting the wrong wattage reading with this voltage problem.
I can hear the aircons fan slowing down and speeding up I have in the last year lost a computer powersupply a kettle 2 powerboards,
Thanks again
grahamfl

Dear ma0641 the power at the moment is 222to223to222to224volts it is changing all the time I have a 40wt light on a small window aircon fridge and freezer and the desktop computer running nothing else I only have other houses around me but funny you should ask about living next door to a plant as my mate next door has a electric lawn mower and each time he turned it on or off I got a 5 volt difference??
I think it is time I got a sparky to look at my power,
Thanks for your time
grahamfl

Without heavy use, you shouldn't see a 30 VAC fluctuation. We have 120VAc here in the ststes and my voltage holds 119-122.